High voltage trench mosfet structure and its fabrication method

Abstract

The present invention discloses a high voltage resistant groove type MOSFET Structure and manufacturing method, groove type MOSFET The structure includes N+ Substrate N- Drift zone P Type base region, source metal, and drain metal, the P The upper part of the base region is formed with N+ Source area, as described N+ On both sides of the source area, there are P+ District; said N+ A trench gate structure is formed in the middle of the source region, which penetrates downwards N+ Source area and extend into P In the basal region; The bottom of the trench gate structure and N- Between the drift zones, there is a N Type zone connection; The upper end of the trench gate structure is covered with an interlayer dielectric layer. In the present invention, P The base region completely wraps around the trench gate structure and forms a N Implementing trench gate structure and N- The connection of the drift region not only reduces gate leakage charges and improves switching speed, but also reduces the electric field at the bottom of the trench, effectively protecting the gate oxide layer and improving reliability.

Images